Hundreds of thousands of people could be kicked off the internet.
Monday, computers worldwide may be infected with a malware virus.
Internet service providers have sent notices, and the FBI set up a special website where you can test your computer.
According to local experts, hackers overseas infected a bunch of machines and while authorities try and fix the problem, the temporary fix will be taken down.
That's why people will have trouble getting online.
Steve Stasiukonis from Secure Network Technologies says, "Monday will be a help desk nightmare in the event that thousands, perhaps millions of people across the country try to call for help.
Joshua Rose from Computer Outlet West says you should take precautions and protect your computer with anti-virus software. "Preventative is always the best but once you're infected, you're infected so it's not going to make a difference if you're on the net or not," Rose said.
Warnings about an attack by hackers have been posted on Facebook and Google.
Experts say don't wait to get help because Monday could be a busy day for help desks.
